Background: The study aimed to establish the prevalence of heavy drinking, evaluate correlations between heavy drinking and socio-demographic factors, physical and psychiatric conditions, and assess the impact of heavy drinking on quality of life and days of work-loss. Methods: Data from a nationally-representative cross-sectional sample were used. The sample comprised 6616 community-dwelling Singaporeans & Singapore Permanent Residents. The main instruments used were the World Mental Health Composite International Diagnostic Interview and EuroQol 5D. Heavy drinking was defined as consumption of 4 or more drinks, or 5 or more drinks in a day in women and men respectively. Results: 12.6% of all adult Singapore residents reported heavy drinking in the last 12 months, and 15.9% reported lifetime heavy-drinking. Strong gender, ethnic, age and income differences were seen. Heavy drinking was positively associated with major depression, the presence of any mood disorder, and with chronic pain. It was also strongly associated with alcohol dependence, alcohol abuse, and nicotine dependence. Heavy-drinkers reported lower quality of life compared to non-heavy drinkers, measured using the EuroQol 5D Visual Analogue Scale. Conclusions: Singapore has a relatively high prevalence of 12-month heavy drinking of 12.6%, and lifetime heavy drinking of 15.9%. Heavy drinking was positively associated with both physical and mental health conditions, and with declines in quality of life. Continued monitoring of heavy drinking behavior and sustained efforts to mitigate the risks associated with heavy drinking is needed.